Anja Wiesner

Structural Proof for the First Dianion of a Polychloride: Investigation of [Cl8]2−

The polychloride salt [CCl(NMe2 )2 ](+) 2 [Cl8 ](2-) was synthesized and crystallized in the ionic liquid [BMP]OTf. The compound was fully characterized by Raman spectroscopy as well as X-ray single-crystal structure determination, and represents the first example of a polychloride dianion to be described. Detailed gas-phase and solid-state calculations concerning the nature of the bonding situation were also performed.

Superacids Based on Pentafluoroorthotellurate Derivatives of Aluminum

The new Lewis acid Al(OTeF5 )3 and its acetonitrile adduct CH3 CN→Al(OTeF5 )3 were obtained by a simple one-step synthesis in batches of up to 15 g. Al(OTeF5 )3 and the adduct were characterized by vibrational spectroscopy (IR, Raman) and quantum-chemical calculations. Furthermore, five different salts of the new weakly coordinating anion [Al(OTeF5 )4 ]- were prepared in a two-step procedure. [Ph4 P][Al(OTeF5 )4 ], Cs[Al(OTeF5 )4 ], [Ph3 C][Al(OTeF5 )4 ], as well as the protonated benzene derivatives [C9 H13 ][Al(OTeF5 )4 ] and [C6 H7 ][Al(OTeF5 )4 ] were characterized by low-temperature single-crystal X-ray diffraction and NMR spectroscopy. Arenium salts have rarely been characterized in the solid state and were synthesized in this work in a simplified fashion.

Taming the High Reactivity of Gold(III) Fluoride: Fluorido Gold(III) Complexes with N-based Ligands

The synthesis of [NMe4 ][AuF4 ] and [NEt4 ][AuF4 ], as well as an improved one-pot synthesis of Cs[AuF4 ], is reported. The new [AuF4 ]- salts were structurally characterized by single crystal X-ray diffraction, NMR spectroscopy, vibrational spectroscopy, and mass spectrometry. These salts are the first gold(III) fluoride salts that can be isolated in pure form and are convenient to be used in usual organic solvents for subsequent synthesis. The formation of molecular AuF3 complexes in solution is further reported, characterized as [F3 Au(NCCH3 )] at low temperature, as [F3 Au(py)] and a binuclear derivative which are stable at room temperature. The stability of these species in common organic solvents was investigated and they showed a satisfying stability.